Natural Selection Begins In The Womb, And It Can Explain Adulthood Conditions

The embryo consists of only about 100 cells and the period it spends in the womb can impact the future health of the individual. According to a new study, natural selection begins in the womb, and it can explain some of the adulthood conditions. At least that’s one of the conclusions of new research carried out by the scientists from the Leiden University Medical Center, Wageningen University and Research, Lund University, Columbia University Mailman School of Public Health in New York.

According to the new study, random alterations in gene expression might be responsible for the survival advantage some embryos possess in comparison with others. After the researchers examined the DNA methylation that controls gene activity, they discovered that a particular region of this DNA is missing in famine-exposed individuals.

Natural Selection Begins In The Womb, And It Can Explain Adulthood Conditions

“We know that a lack of nutrition decreases the likelihood of an embryo to survive. Our new study indicates that surviving famine in the uterus hinged on having a DNA methylation pattern allowing continued growth of the embryo in spite of limited resources. But those same methylation patterns may have adverse health effects much later in life,” said Bas Heijmans from the Leiden University Medical Center.

Natural selection is involved in filtering various genetic variations to help the embryo adapt to the environment. DNA methylation variants could improve an embryo’s chance of survival when the conditions are harsh, especially regarding nutrition.

“We have always struggled to explain how early embryos would be able to modify specific epigenetic marks in response to nutrition. It is fascinating that selective survival based on random epigenetic variation fits the data best”, said Tobias Uller from the Lund University.

“These findings have often been interpreted as conclusive proof of fetal adaptations in the womb that will lead to adult disease if the adult environment changes for the better. But our findings point to a different mechanism”, concluded L.H. Lumey from the Columbia Mailman School.